Art of retting flax



B. S. SUMMERS.

ART OF RETTING FLAX.

APPLICATION FILED DECLZ, 1918.

Patented Nov. 30, 1920.

I l i vim 1 1 IH 1 M 1 1 UNITED. STATES -,mxrrrzr om-lice.

BER-TRAND s. SUMMERS, or roar HURON, MICHIGAN.

ART OF BETTING FLAX.

Specification of Letters Patent. Patented NOV. 30, 1920.

Application filed December 2, 1918. Serial No. 264,882.

tirely within doors, and is therefore independent of theseason-and weather. As retting, which is due to a species of fermentation, is ordinarily and most advantageously carried out at temperature between 70 and 90 Fahrenheit, it is necessary, when the atmospheric temperature is below that indi-v 'eated to artificially heat the water in which the retting is being performed to the required degree.

It is known in the art that circulation betters the result obtained in retting. This circulation heretofore has been obtained by the introduction of fresh water into the tanks containing the straw being subjected to retting, the displaced liquor being allowed to flow to waste.

It is known in water retting that too much fresh water gives inferior results, while if the retting water becomes too foul, on the other hand, inferior results, usually of a different nature are noticed. Fine fiaxes, therefore, require certain density of bacterial action, for best results. When this is attempted by the introduction of controlled amounts of fresh water, the operation is both crude and expensive, and the operation is either overdone or underdone.

In severe weather, very considerable amounts of fuel are required to bring these additions of fresh Water to the requisite temperature. I have discovered that the deleterious effect of the foul liquor in the retting operation is mainly due to t he solid by-products'generated by the enzymlo action of' retting, and when these are removed from old liquors, very much greater quantities of old liquor can be utilized with good effect. In fact, goodresults may be obtained by simply replenishing," the liquor taken out by wet flax and evaporatlon. .I prefer, however to use in some cases more than this amount of fresh water, but n every case the liquor is mainly constituted from the filtered liquor of previous rettings.

When the liquor used in retting the flax is filtered, no deleterious effects result by the employment of large quantities of the old liquor.

In practising my invention I have preferably standardized the liquor so that the relative proportions of the old and new liquor may be controlled. For this purpose I titi'ate the liquor with a suitable standard ized solution of permanganate of potash,

which in oxidizing the organic matter of the liquor, loses its color, and by noting the oxidizing action of this standard solution of permanganate of potash on a measured quantity of the retting liquor, I am able to proportion a bath with a liquor suitable to the flax under the retting operation, as the removal of the solid decomposed products allows the employment of relatively large quantities of the old liquor. In this way, I am able to get the required terial action without introducing into the retting liquor too much of the by-products of retting that have a deleterious effect.

I have discovered that the reason that better results are obtained where fresh water in limited quantities is introduced, is that the insoluble products generated by the fermentation produce certain deleterious effects, on the'retting operation, and that the advantage which follows from the slow addition of fresh water is due to the removal of these by-products from the neighborhood of the quor, itcan be with relatively small increments of resh water, with entirely satisfactory results. Ordinarily fresh water in sufficient quantities to replace that removed from the sysor intermittent circulation ,of the retting water through the retting tank or vat accompanied by the continuous or intermittent removal from the liquid of the insoluble density of bac- I flax, and that if the by-products are continually removed from the retting used over and over a ain,

by-products resulting from the fermenta- 1 tion. The invention may be practised in a -my invention; Fig. 2 is a side elevation thereof, and Fig. 3 is a vertical longitudinal section of a portion of the device on the line 33 of Fig. 1.

The installation comprises a suitable or desired number of retting tanks 4 which may be of usual or approved construction and ,are adapted to contain each a desired quantity of straw to be retted. At one end of the series of retting vats is a filter 5 which ingeneral construction may be similar to the retting vats and is adapted and designed to removelthe insoluble products of the retting fermentation by circulating the liquids from the retting vats through said filter. This filter should be of sufficient size to accommodate considerable supplies of old liquor so that as new. vats are made up, this supply may be drawn upon to make a liquor for the new vats, or if desired, an odd storage tank may be supplied, or one of the battery of retting vats used for. the storage of retting'liquor. In the particular form of filter shown a grid 6 is supported in the filter tank 7 a suitable distance above the floor thereof and is covered with a layer 8 of several inches of excelsior which forms a support for a bed of filter sand 9, as seen in Fig. This form of filter answers the purpose satisfactorily though other forms may be employed if desired.

The retting liquor from the several tanks is conveyed to the filter by an overflow trough 1O communicating with each of the vats, and the filtered liquor is returned from the .bottom of the filter to the respective vats by means of a pipe 12'leading from .the bottom of the filter, a pump 13 to the inlet of which said pipe is connected, and a manifold e14 provided with branches 15 leading to the respective retting vats. Valves 16 control the branches, and a valve 17 controls the connection of the filter to the inlet of the pump. The pump is constantly operating during the normal rettlng operation, drawingthe liquor from the bottom of the filter and discharging it into the bottom of the respective vats in which it rises through the flax straw within the vats and returns through the overflow conduit to the top of the filter. lhe liquor carries the insolubles from the retting action with it to the filter where they are separated by the sand et cetera. The inlet of the pump is also connected by a manifold-.18 and branch pipes 19 to the bottoms of the respective tanks. and the discharge manifold 14 has a alve controlled waste outlet 20 whereby when desired any or all of the tanks may be emptied through the pump. Normally however the branch pipes 19 are closed by the valves 21. The filter is provided with in overflow 22. and a pipe 23 connected to asuitable source of water supplies the retting vats with additional water when desired through the valve-controlled branches 24. The temperature of the retting vats may be maintained by any desired means or by the "emperature of the compartment or building in which the vats are installed, and,

therefore. I have not deemed 'it necessary to show any particular form of heating means.

The retting operation is in the main conducted. as usual. The retting liquor however is continually circulated through the vats and filter as described, being led off from the upper level of the vats with the contained insoluble matter into the upper part of the filter tank whence it flows down throu 11 the filtering material and is returne by the pump to the bottoms of the respectivevats. the flow being regulated by the hand valves as heretofore described. If it is desired to empty the filter or any or all of the vats. this may bedone by opening and closing proper valves. If a vat is to be drained. for example, if valve 21 is opened, and valve 17 controlling the connection of the pump to the filter is closed. theliquor thus drawn from the vat to be emptied may be discharged by means of the pump into the circulating system and through the other vats by means of the overflow to the filter or to the storage tank, or the valve 16 maybe closed. and the valve 20 opened, the liquor discharging to the sewer.

Likewise in setting a newbath, a suitable amount of the old liquor is drawn from the filter or the storage tank, and a certain amount of new water mixed with it to bring it to standard. and when the bath thus made up is brought to suitable temperature by operating suitable valves, it is made part of the circulating system. Any excess liquor may be discharged through the valve 20 and the sewer, or may be allowed to go to the sewer through the overflow of the filters 22.

To replenish the filter new sand or gravel or like material may be supplied or the old material may be removed from the filter, dried and agitated, in any suitable device, such as a tumbling barrel or cement mixer, and then, properly screened, when the mabath of retting liquor and removing the insoluble products only-from the bath. I

2. "A process of retting which consists in circulating a retting liquor through the material to be retted, conducting the liquor through a filter and returning it from the filter to the material. to be retted.

3. A process of retting which consists in subjecting the material to be retted to the retting liquor, withdrawing the liquor from above the materialbeing retted, filtering the liquor, and returning it beneath the material belng retted. p

4. The herein described process of retting which consists submittlng the material to bevretted to a bath ofretting liquor in a .vat; circulating the retting liquor through a filteringmedmm to remove the solid matters contained therein, returning the filtered liquor to the vat, and supplying additional water to compensate for waste.

v 5. The herein described process of retting which consists in submitting the material to be retted to a retting liquor composed of a mixture of liquors from former rettings I q a properly filtered and fresh water,

properly standardized as described.

6. In a retting system, a retting vat, a

V filter, and means for circulating the retting medium throughthe vat and filter. a

7. In a retting system, a vat, a filter, an

overflow connection from the top of the vat.

to the filter, and means for returning the filtered liquor fromthe filter to the bottom of the vat.

8. In a retting system in combination one or more retting vats, a filter, a pump, both the suction and discharge sides of which are connected with the bottom of the retting tanks by separate pipes and an overflow conduit connecting the top of each retting tank with the top of the filter substantially as described. l

9. In a retting system in combination one or more retting tanks, a filter, a pump, suitable connections, and valves and a storage tank substantially as described.

10.,A process of retting which consists in circulating a retting liquor through the material to be retted, filling it and returning it from the filter to the material to be retted, when suflicient solid particles have thus been filtered out, drying the filtering medium and removing the said solid particles by agitation and screening substantially as described.

. BERTRAND S. SUMMERS. 

